/* ====================================================================
 * Copyright (c) 1995-1998 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */

#include "httpd.h"

/*
 * Given a string, replace any bare " with \" .
 */
API_EXPORT(char *) ap_escape_quotes (pool *p, const char *instring)
{
    int newlen = 0;
    const char *inchr = instring;
    char *outchr, *outstring;

    /*
     * Look through the input string, jogging the length of the output
     * string up by an extra byte each time we find an unescaped ".
     */
    while (*inchr != '\0') {
	newlen++;
        if (*inchr == '"') {
	    newlen++;
	}
	/*
	 * If we find a slosh, and it's not the last byte in the string,
	 * it's escaping something - advance past both bytes.
	 */
	if ((*inchr == '\\') && (inchr[1] != '\0')) {
	    inchr++;
	}
	inchr++;
    }
    outstring = ap_palloc(p, newlen + 1);
    inchr = instring;
    outchr = outstring;
    /*
     * Now copy the input string to the output string, inserting a slosh
     * in front of every " that doesn't already have one.
     */
    while (*inchr != '\0') {
	if ((*inchr == '\\') && (inchr[1] != '\0')) {
	    *outchr++ = *inchr++;
	    *outchr++ = *inchr++;
	}
	if (*inchr == '"') {
	    *outchr++ = '\\';
	}
	if (*inchr != '\0') {
	    *outchr++ = *inchr++;
	}
    }
    *outchr = '\0';
    return outstring;
}
